If you are like most people, you probably freak out when you hear the words transmission repair. Most people do not understand that much about transmissions, other than that they can cost a lot to repair. However, you actually have a few options when it comes to repairing your transmission. Diagnostics The first thing any good mechanic will do is run a full diagnostic on your transmission. After they have ran a full diagnostic on your transmission, they will be able to tell you what it wrong with it as well as what needs to be done in order to get you back on the road.